Unable to carry out operations (create trigger, drop table) for a table I created

I am using a SQL Server database with SQL Server Management Studio where I have existing tables. I add a few tables to it and it works just fine. However, for subsequent operations such as

Drop table XXX --OR 
Create Trigger YYY on XXX

I run into a error statement that reads:

i) Cannot drop table XXX as it does not exist or you do not have permissions

ii) The object 'XXX' does not exist or is invalid for this operation

I tried to carry out an Insert operation but that showed me a similar error (The object 'XXX' does not exist). I can see this开发者_Python百科 maybe a permissions issue since I am using an existing database. However, in that case, I should have been unable to create a table as well?

Can anyone pinpoint how I can work myself around this and what the problem is?

What is your default schema?

SELECT name, default_schema_name 
    FROM sys.database_principals 
    WHERE type = 'S';

Try qualifying your references to the table as SchemaName.XXX and see if that helps.

Most of times when I had similar situations tables were created in system databases (master, tempdb..). Of course it was my mistake. So maybe try to search for a tables in other databases?